I can't say that I have ever tried making sushi at home, but this roller design from Osko+Deichmann makes it seem like even the uninitiated could get the job done.

Apparently, it works in a similar fashion as an old-timey cigarette roller with the seaweed being wrapped around the core with a few turns of the handle. It's only a concept at this point, but I don't see any reason why it couldn't make the leap to a real world product. [Osko+Deichmann via Domestic Geek via Gearfuse]